HV Switchgear & Ring Main Units (12–40.5kV) | KYN28A-12, HXGN15-12, LPG-12

Overview

Jingmin Electric supplies two families of medium voltage switchgear: metal-clad withdrawable switchgear for distribution rooms and substations, and ring main units (RMUs) for compact ring networks, wind farms, underground substations and outdoor enclosures.

All enclosures, busbars, mechanisms and secondary wiring are made in our own workshops. Interrupters and instrument transformers fitted inside are also our own production — which is why we can offer both competitive pricing and short lead times on custom schemes.

12 kV, 24 kV and 40.5 kV ratings
Single or double busbar, up to 4000 A
Vacuum, SF6, SF6-free eco-gas, solid-insulated and air-insulated options
Mechanical and electrical interlocks per IEC 62271-200
Optional intelligent monitoring, FTU/DTU and communication interfaces

Typical delivery: 25–45 days after drawing approval, depending on scheme complexity and quantity.

Documents supplied: general arrangement drawings, single-line diagram, secondary wiring diagram, routine test report, installation & operation manual.

Ask for a Scheme Proposal

KYN28A-12 Metal-Clad Withdrawable Switchgear

The workhorse of 12 kV distribution rooms — withdrawable handcart, independent pressure relief, cable or busbar compartment options.

KYN28A-12 — typical technical data
Parameter	Unit	Value
Rated voltage	kV	12
Rated frequency	Hz	50 / 60
Power-frequency withstand voltage (1 min)	kV	42 (phase–earth / phase–phase)
Lightning impulse withstand voltage	kV	75
Rated current	A	630 / 1250 / 1600 / 2000 / 2500 / 3150 / 4000
Rated short-circuit breaking current	kA	20 / 25 / 31.5 / 40
Rated short-time withstand current (4 s)	kA	20 / 25 / 31.5 / 40
Rated peak withstand current	kA	50 / 63 / 80 / 100
Busbar arrangement	—	Single or double busbar
Degree of protection	—	IP4X (enclosure), IP2X (door open)
Typical dimensions W × D × H (1250 A)	mm	800 × 1500 × 2300
Ambient temperature	°C	−15 to +40
Standards	—	IEC 62271-200, GB 3906

Dimensions vary with rated current, busbar arrangement and cable compartment. Special widths available for 3150 A and 4000 A schemes.

Compartments

Busbar compartment, handcart (breaker) compartment, cable compartment and LV compartment, each pressure-relieved independently.

Interlocking

Breaker cannot be racked in or out with the door open or the earthing switch open — mechanical and electrical interlocks as standard.

Breaker options

VS1 / ZN63A indoor vacuum circuit breaker as standard; other compatible withdrawable units on request.

KYN61-40.5 & XGN66-12

40.5 kV withdrawable switchgear for sub-transmission and large plants; fixed-type cubicles where the budget or floor space demands a simpler scheme.

KYN61-40.5 — typical technical data
Parameter	Unit	Value
Rated voltage	kV	40.5
Power-frequency withstand voltage (1 min)	kV	95
Lightning impulse withstand voltage	kV	185
Rated current	A	1250 / 1600 / 2000 / 2500
Rated short-circuit breaking current	kA	20 / 25 / 31.5
Rated short-time withstand current (4 s)	kA	20 / 25 / 31.5
Rated peak withstand current	kA	50 / 63 / 80
Typical dimensions W × D × H	mm	1400 × 2800 × 2600 (single busbar)
Standards	—	IEC 62271-200, GB 3906

XGN66-12 — typical technical data (fixed type)
Parameter	Unit	Value
Rated voltage	kV	12
Power-frequency withstand voltage (1 min)	kV	42
Lightning impulse withstand voltage	kV	75
Rated current	A	630 / 1250
Rated short-circuit breaking current	kA	20 / 25
Rated short-time withstand current (4 s)	kA	20 / 25
Typical dimensions W × D × H	mm	1000–1200 × 1200 × 2650
Busbar	—	Single busbar, top or bottom entry
Standards	—	IEC 62271-200, GB 3906

Ring Main Units & Compact Switchgear

Modular, extendable or sealed-for-life — choose the insulation technology that suits your climate, maintenance policy and procurement rules.

Ring main unit comparison — typical technical data
Model	Insulation	Rated voltage	Rated current	Short-circuit (3–4 s)	Switching device
HXGN15-12	SF6	12 kV	630 A	20 kA	SF6 load break switch / vacuum CB (V module)
HXGN17-12	Air / vacuum	12 kV	630 A	20 kA	Vacuum load break switch
RM6-12 / RM6-24	Sealed SF6	12 / 24 kV	630 A	20 kA	SF6 LBS + vacuum CB
LPG-12	Solid (epoxy)	12 kV	630 A	20 kA	Vacuum, fully sealed, maintenance-free
XGN-12/630	SF6-free eco-gas (dry air / N₂)	12 kV	630 A	20 kA	Vacuum
XGW-12	SF6 or solid	12 kV	630 A	20 kA	Vacuum, with FTU / DTU for automation
HWX-12	Air	12 kV	630 A	20 kA	Outdoor switching station, 2–4 ways

Modular notation (C / F / V / D)

Ring main units are described by their module chain, e.g. C–F–V–C:

C — cable connection module (incoming / outgoing feeder)
F — switch–fuse combination module (transformer protection up to 125 A)
V — vacuum circuit breaker module (larger transformer or line protection)
D — direct busbar connection / busbar riser module
S — metering or busbar sectionalizing module

Selection notes

Three points decide most RMU choices:

Extensibility — sealed units (RM6, LPG-12) cannot be expanded later; HXGN15/HXGN17 can.
Gas policy — many utilities now restrict SF6; choose LPG-12 or XGN-12/630 eco-gas.
Automation — for SCADA / remote control choose XGW-12 with motorised mechanisms, CT/PT and FTU.
Environment — outdoor use requires HWX-12 or an RMU inside an IP54 enclosure.

HV Switchgear & Ring Main Units